In order to make it easier to read the time when the watch is worn on the wrist, or to enable it to be used as a table clock, it has long been proposed to have a first stationary case, attached to the wrist by the strands of a bracelet or wristband or able to be placed on a table, and a second case, which contains the watch movement and is mobile and hinged in the first case, and which can take a first position in which it is locked in the stationary case and a second position in which it can adopt an inclined position.
U.S. Pat. No. 1,804,048 already discloses a device wherein the mobile case can be unlocked by pressing a push-button passing through the middle part of the watch. In CH Patent No. 161 610, the display is concealed when the two cases nest inside each other, and made visible by pivoting the mobile case by gripping a lip arranged at 12 o'clock. In the device disclosed in CH Patent No. 343 946, one side of the middle part of the stationary case is removed to allow a corresponding middle part portion of the mobile case to be gripped in order to unlock the latter against the bias of a spring and pivot said case. In U.S. Pat. No. 4,168,607, the mobile case is also brought into a raised position via the action of a strip spring arranged in the back cover of the stationary case, by pressing a push-button as in the first document cited.
These devices of the prior art may protect or conceal the crown or another control member, but they have the drawback of either leaving a push-button or an unlocking lip visible, or of comprising a recess in the middle part, which, in both cases, is awkward to manipulate or unattractive.